P0237

What it means

P0237 means the engine control unit has seen the signal voltage from the turbocharger or supercharger boost pressure sensor 'A' fall below the expected range. This usually points to a short to ground, an open circuit, a missing sensor supply voltage or a faulty sensor. The exact voltage thresholds and sensor location vary by model and engine.

Symptoms

• Engine warning light on
• Loss of power or poor acceleration
• Car may go into limp mode with limited boost
• Hesitation or flat spots under load
• Poor fuel economy
• Rough running or black or white smoke in some cases

Possible causes

• Faulty boost pressure sensor reading low or failed internallylikely
• Damaged wiring, signal wire shorted to ground or open circuitlikely
• Corroded, loose or contaminated sensor connector or terminalslikely
• Missing or low 5 volt reference supply to the sensor, or poor sensor groundpossible
• Blocked, split or disconnected boost sensor pipe or port, on systems where the sensor is remote-mountedpossible
• Real boost leak or turbocharger fault causing very low actual boost pressurepossible
• Fault inside the engine control unitrare

How to diagnose

1. Read all stored and pending codes and note the freeze frame data, including engine load, rpm and boost or manifold pressure at the time of setting.
2. Look for other sensor circuit codes sharing the same 5 volt supply, as these point to a common supply or ground fault.
3. Inspect the sensor, connector and wiring for damage, chafing, heat damage, oil contamination, water ingress and corrosion.
4. Check any hoses or pipes feeding the sensor for splits, blockages or loose connections.
5. With the ignition on, check the sensor supply voltage and ground against the manufacturer's wiring data.
6. View live data with the key on and engine off and compare the reading with ambient pressure, then check it responds correctly under load.
7. Test the signal wire for a short to ground or an open circuit, with the connector disconnected and following the wiring diagram.
8. Inspect the intake and charge air system for leaks and check turbocharger operation if the live data suggests low real boost.

How to fix

• Replace the boost pressure sensor if it reads out of range or fails testing.
• Repair or replace damaged wiring and clean or renew corroded connector terminals.
• Restore the sensor supply or ground by repairing the circuit fault, following the model-specific wiring diagram.
• Replace split, blocked or loose sensor pipes and fix any charge air leaks.
• Repair or replace the turbocharger or its control components if a genuine boost fault is confirmed.

Can I keep driving?

Nearby codes

• P0236GenericTurbocharger/Supercharger Boost Sensor A Circuit Range/Performance
• P0238GenericTurbocharger/Supercharger Boost Sensor A Circuit High